There’s an incredibly rocky start to The Switch. An opening voiceover from the main character talks about how people are always in a hurry — footage of a busy New York City playing underneath — ending with that pun about being part of the “human race.” The main character is then revealed to be a neurotic, self-absorbed, pessimistic hypochondriac, who still has feelings for his former girlfriend and current best friend, and blah, blah, blah.

That ex/best friend has had enough trying to find a man with whom to start a family and wants to take matters into her hands. “Life is in session,” she keeps saying, and blah, blah, blah.

She wants him to help her find a good man to donate his sperm. “What’s wrong with my sperm,” he queries, and she responds that they’re best friends and he’s neurotic and pessimistic. He doesn’t think she should go through with this, and she gets annoyed, calls him judgmental, and blah, blah, blah.

On and on the opening act of The Switch goes, until finally Kassie (Jennifer Aniston) finds a sperm donor, holds a Hawaiian-themed artificial insemination party, and invites best friend Wally (Jason Bateman) after an uncomfortable break in the friendship. The donor, Roland (Patrick Wilson), is a nice enough guy — married, a professor of feminist literature, and the eye candy at Kassie’s party — but Wally doesn’t care.

He’s drunk, and Kassie’s annoying buddy, Debbie (Juliette Lewis), has given him a potent herbal pill to calm him down. He wanders into the bathroom where Roland’s contribution to the evening is, ruins it in a certain purposeful accident, and has to replace it with his own donation. In the movie’s first successful joke, which turns into a running one, he uses the only visual material on hand to aid in the process.

Seven years pass, and Allan Loeb’s screenplay (based on a short story by Jeffrey Eugenides) shifts gears from its theme-grasping and loaded exposition. Kassie leaves town and has the baby; she and Wally drift apart. She moves back to the city, and Wally is directly confronted with becoming a father figure without realizing (thanks to a convenient blackout that eliminates any despicable motive from his actions) that he is actually a father.

The son is Sebastian (played with endearing sincerity and admirable comic timing by Thomas Robinson), who, just like his dad, is a neurotic hypochondriac, horrified to learn that he suffers from hypochondria.

In the first of many unfortunate turns for her character’s development, Kassie, who makes a strong, independent choice to become a single mother, decides to start talking and dating Roland, who, thankfully, is not presented as an obstacle for Wally. Roland is recently divorced, suffering from some unattended issues regarding the ending of his marriage, and wants to become involved — at the wish of Kassie — in Sebastian’s life. He takes Wally out for a drink after a failed attempt to throw a birthday party for the boy, and it’s not to rub Wally’s nose in the fact that he’s dating Kassie. No, Roland simply wants to understand why Sebastian would rather have a birthday party at an animal shelter than a climbing wall. The kid’s different from him; surely Wally, whom Sebastian likes, can give Roland advice.

We aren’t manipulated to dislike Roland for reasons of cosmetic conflict. We become involved in the way Wally and Sebastian take to one another, visiting the zoo, asking for and giving (bad) advice about bullies, and showing they have feelings of being without a father. Even when Wally, with some help from his own father-figure boss (an affably goofy Jeff Goldblum), finally remembers the fateful night he swapped samples in the bathroom (in a scene punctuated with euphemisms for semen), he has believable reason to withhold the information from Kassie: He has a good thing going with Sebastian and doesn’t want to ruin it.

Then the movie falters, as Wally decides to tell the truth, continues to hold back, and erupts at the most inopportune time. In a script that has endeared itself with surprising sincerity, it becomes insincere. In Loeb’s biggest insult to her character, Kassie, already now weak and defined only by her confusion in choosing between Roland and Wally, makes a life-changing decision based on two quick shots of her thinking.

The Switch ends where it started, reaching for meaning in narrated trite phrases, and it’s a massive disappointment. Here is a movie that pulls itself up from a rambling, uninteresting start only to fall right back in the same hole.

Mark Dujsik is a member of the Chicago Film Critics Association and the Online Film Critics Society. For more of his reviews, visit his website.